Figured this would be a good thread to get going. I learned a new one earlier when I started wondering: if something can be new-fangled, can it be old-fangled? Just plain fangled? Turns out 'fangle' is an old word meaning 'create, manufacture, build, invent,' so yes, it sure can.
Also, I'd never realized 'technetronic' was a real word, but apparently it is, meaning exactly what it sounds like. Note that it's 'techn-e-tronic', not 'techn-o-tronic' as you might expect.
Other good ones: ultracrepidarianism, the practice of acting like you know what you're talking about when you don't; jiggery-pokery, underhand scheming; zenzizenzizenzic, raised to the eighth power.

Everybody loves using things as other things, right? Check out my blog at the Cromulent Bricoleur and see one hipster's approach to recycling, upcycling, and alterna-cycling (which is a word I just made up).

My daughter came home from school several years ago, amazed and bewildered because she heard her teacher say he was "dying of heat prostration" - but how could that be? It wasn't a real saying! She was convinced, absolutely and completely convinced, that "heat prostration" was something that my husband and I had made up and we said it just because we liked the sound of it.